Immunotherapy and Radioimmunotherapy for Desmoplastic Small Round Cell Tumor

Cellular therapeutic potential of genetically engineered stem cells in cancer treatment

Traditional therapeutic approaches in the treatment of cancer have many side effects and are often ineffective and non-specific, leading to the development of therapy-resistant tumour cells. Recently, numerous discoveries about stem cells have given a new outlook on their application in oncology. Stem cells are unique because of their biological attributes, including self-renewal, differentiation in different types of specialized cells and synthesis of molecules that interplay with tumour niche. They are already used as an effective therapeutic option for haematological malignancies, such as multiple myeloma and leukaemia. The main goal of this study is to investigate the possible applications of different types of stem cells in cancer treatment and to summarize novel advances, as well as the limitations of their application in cancer treatment. Research and clinical trials that are underway revealed and confirmed the enormous potential of regenerative medicine in the treatment of cancer, especially when combined with different nanomaterials. Nanoengineering of stem cells has been the focus of novel studies in the area of regenerative medicine, such as the production of nanoshells and nanocarriers that enhance the transport and uptake of stem cells in their targeted tumour niche and enable the effective monitoring of stem cell effects on tumour cells. Although nanotechnology has a lot of limitations, it provides new opportunities for the development of effective and innovative stem cell therapies.

Effective Treatment of Anlotinib Combined With Chemotherapy in Children With Desmoplastic Small Round Cell Tumor: A Case Series in a Single-center and Literature Review

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is a highly aggressive primitive sarcoma with a 5-year survival rate estimated at only 15% to 30%. Although few curative treatment options exist, patients are most often treated with a combination of aggressive chemotherapy, radiation, and surgery. Targeted therapy inhibitors of platelet-derived growth factor A, insulin-like growth factor receptor 1, and vascular endothelial growth factor receptor-2, which are almost uniformly overexpressed in DSRCT, have largely failed in clinical trials. Anlotinib is a multitarget receptor tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor 1-3, fibroblast growth factor receptor 1-4, platelet-derived growth factor receptor α/β, c-Kit, and Met. In this study, we presented 3 cases of DSRCT treated effectively with anlotinib combined with chemotherapy.

CASE PRESENTATION

Three children DSRCT patients were enrolled from September 2020 to December 2021 and monitored until August 30, 2022. The clinical data were prospectively studied. The peritoneal cancer index classified all 3 patients as stage IV. After surgery, all 3 patients received anlotinib in combination with chemotherapy and reacted to the medication. For all 3 patients, clinical symptoms were substantially eased, and the size of the masses was reduced. Patient 1 and patient 3's progression-free survival had been extended, and anlotinib was continued as a maintenance medication in the 2 patients who were in good health at the end of the follow-up. Patient 2 died of postoperative complications 1 month after second-stage surgery. The main side effects of anlotinib were fatigue and hypertension. However, its toxicity was controllable and tolerable in children patients.

CONCLUSIONS

This is the first report that anlotinib is effective in children with DSRCT. This report may provide an additional option for the treatment of metastatic DSRCT.

Desmoplastic small round cell tumor of the liver: diagnosing a rare case on liver biopsy

Desmoplastic small round-cell tumors (DSRCT) frequently develop in the retroperitoneum, pelvis, omentum, and mesentery. Here, we present an unusual case of primary DSRCT in the liver. The patient was an 11-year-old boy with multiple solid masses in the liver parenchyma. The tumor in the needle biopsy had a histology revealing a small round cell morphology and desmoplasia. It shows the immunohistochemical features of DSRCT and documentation of EWSR1-WT1 fusion.A potential diagnostic pitfall is exerted when evaluating liver biopsy, in which DSRCT is a great mimicker and may be easily confused with more common liver malignancies of childhood, such as hepatoblastoma, calcifying nested stromal-epithelial tumor, undifferentiated embryonal sarcoma, and other small round cell tumors, as well as the fibrolamellar variant of hepatocellular carcinoma. This distinction is critical because an accurate therapeutic approach requires a correct diagnosis.

Intra-abdominal desmoplastic small round cell tumor: The European pediatric Soft tissue sarcoma Study Group (EpSSG) experience

BACKGROUND

This study describes the clinical findings of a consecutive series of pediatric and adolescent patients with a diagnosis of intra-abdominal desmoplastic small round cell tumor (DSRCT) prospectively enrolled in European pediatric Soft tissue sarcoma Study Group (EpSSG) protocols: the BERNIE study, the EpSSG MTS 2008 study, and the EpSSG NRSTS 2005 study.

METHODS

Patients aged less than 21 years with a diagnosis of DSRCT arising in the abdomen were included. All trials recommended a multimodal approach including intensive multidrug chemotherapy and loco-regional treatment with surgery and/or radiotherapy whenever possible.

RESULTS

The analysis included 32 cases (median age 13.7 years, male:female ratio 1.5:1). Three patients had localized tumors, seven had regionally disseminated disease, and 22 extraperitoneal metastases. All but one patient received multidrug chemotherapy and 11 had maintenance chemotherapy. Loco-regional treatment consisted of surgery only in seven cases, surgery plus adjuvant radiotherapy in 10, and radiotherapy only in six. Among the 17 cases who had radiotherapy, six had irradiation of the primary site, 10 had whole abdominopelvic radiotherapy plus boost to macroscopic residual disease, and one had irradiation to lung metastases only. With a median follow-up of 76 months (range: 18-124 months), 5-year event-free and overall survivals were 19.7% and 21.0%, respectively. Event-free survival was significantly worse for patients who did not receive loco-regional treatment (p-value .007).

CONCLUSIONS

The study confirmed that the outcome of patients with DSRCT remains dismal and did not improve over recent years despite an intensive multimodal treatment approach.

Identification of immunotherapy and radioimmunotherapy targets on desmoplastic small round cell tumors

Background

Development of successful antibody-based immunotherapeutic and radioimmunotherapeutic strategies rely on the identification of cell surface tumor-associated antigens (TAA) with restricted expression on normal tissues. Desmoplastic small round cell tumor (DSRCT) is a rare and generally neglected malignancy that primarily affects adolescent and young adult males. New therapies capable of treating disseminated disease are needed for DSRCT, which is often widespread at diagnosis.

Methods

We used immunohistochemistry (IHC) on fresh frozen surgical specimens and patient-derived xenograft (PDX) tumors and flow cytometry on DSRCT cell lines to evaluate expression of TAAs in these tumors. In vitro cytotoxicity assays were used to evaluate the efficacy of T cell-engaging bispecific antibodies (T-BsAbs) directed at these targets. In vivo, we used an intraperitoneal xenograft mouse model of DSRCT to test T-BsAbs against several TAAs.

Results

In DSRCT specimens we found widespread expression of B7-H3, EGFR, GD2, HER2, mesothelin, and polysialic acid, clinical targets for which specific antibody therapeutics are available. The expression of B7-H3, EGFR, HER2, and mesothelin was confirmed on the cell surface of DSRCT cell lines. In vitro cytotoxicity assays confirmed the efficacy of T cell-engaging bispecific antibodies (T-BsAbs) directed at these targets against DSRCT cells. Remarkably, a HER2xCD3 T-BsAb was capable of completely shrinking established tumors in an intraperitoneal mouse model of DSRCT.

Conclusions

We propose that these TAAs should be further investigated in preclinical models as targets for immunotherapy and radioimmunotherapy with the hope of providing a rationale to extend these therapies to patients with advanced DSRCT.

Intra-Abdominal Desmoplastic Small Round Cell Tumor (DSRCT) and the Role of Hyperthermic Intraperitoneal Chemotherapy (HIPEC): A Review

Desmoplastic small round cell tumor is a very rare and highly aggressive soft tissue sarcoma, usually presenting with multiple intra-abdominal tumors in young males. Patients present with advanced disease and the overall survival is dismal. Multiple studies report relatively favorable outcomes with multimodal treatment consisting of chemotherapy, surgery and radiotherapy. If resection is feasible, complete cytoreductive surgery is the cornerstone of surgical treatment. The benefit of hyperthermic intraperitoneal chemotherapy in addition to cytoreductive surgery is unclear, and few studies have evaluated this option. We sought to identify the role of hyperthermic intraperitoneal chemotherapy in patients with intra-abdominal desmoplastic small round cell tumor. Our review of the available literature revealed no clear survival benefit in performing hyperthermic intraperitoneal chemotherapy after cytoreductive surgery.